THESAURUS
hold water
afford proof of, ascertain, be consistent, be demonstrable, be irrefutable, be logical, be reasonable, be the case, be true, be truthful, bring home to, cinch, clinch, conform to fact, demonstrate, determine, establish, figure, fix, follow, follow from, have a case, hold, hold good, hold together, hold true, hold up, make good, make out, make sense, nail down, prove, prove out, prove to be, prove true, remain valid, remove all doubt, set at rest, settle, settle the matter, show, stand the test, stand to reason, stand up, stick together, wash
ROGET THESAURUS
hold water
Demonstration
VB
demonstrate, prove, establish, make good, show, evince, manifest, confirm, corroborate, substantiate, verify, settle the question, reduce to demonstration, set the question at rest, make out, make out a case, prove one's point, have the best of the argument, draw a conclusion, follow, follow of course, follow as a matter of course, follow necessarily, stand to reason, hold good,
hold water, convince, persuade (belief).
Truth
VB
be true, be the case, sand the test, have the true ring, hold good, hold true,
hold water, render true, prove true, substantiate, get at the truth.